JPS59230853A - Prevention device of lock of wheel - Google Patents

Abstract

PURPOSE:To make release of a brake reliable and to improve safety, by providing a bypass route allowing only a reflux of hydraulic pressure to a master cylinder side by detouring a normally opening type solenoid valve provided in a main route for transmission of brake hydraulic pressure. CONSTITUTION:A solenoid operating type normally opening type first valve 9 is provided within a main route 8 connected between a space from a master cylinder 2 generating hydraulic pressure according to step-on force of a brake pedal 1 to a brake gear 7. A normally closing type second valve 15 and a pump mechanism 21 for pumping up a hydraulic liquid are connected as a connecting part with a bypass flow duct 14 connected with the main route 8 through a bypass, and a reservoir mechanism 26 is provided in the midst of the bypass route 14. A second bypass route 30 provided with a relief valve 31 allowing a reflux of hydraulic pressure in the direction of an input port 4 is connected between the input port 4 and an output port 5 within the main route in addition to the above constitution so that release of the hydraulic pressure in the inside of the brake gear 7 at the time of release of a brake can be done reliably.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in wheel lock prevention devices used in vehicles such as motorcycles and four-wheeled vehicles, and more specifically, to a brake fluid pressure transmission system, and relates to a reservoir mechanism for releasing fluid pressure and this reservoir mechanism. This article relates to a wheel lock prevention device of the type in which a pump mechanism for circulating brake fluid back to a brake fluid pressure transmission system is bypass-connected.

Conventionally, anti-skid devices have a large pneumatically operated pressure reducing device, but when it is necessary to lower the brake fluid pressure,
A switching valve-type anti-static system that releases pressure fluid from the brake fluid pressure transmission system to the reservoir mechanism, and when the brake fluid pressure needs to rise again, the fluid stored in the reservoir mechanism is returned to the brake fluid pressure transmission system using a pump mechanism. A skid device (wheel lock prevention device) has been proposed and is known to have the characteristic of being suitable for miniaturization due to its construction.

As one of the configurations of such a switching valve type wheel lock prevention device, the following configuration can be considered.

In other words, the brake fluid pressure transmission path (hereinafter referred to as the main path) that connects the mask cylinder (hydraulic pressure generation source) and the brake equipment is a normally open type that is normally open and closed when the brake fluid pressure needs to drop. A first switching valve (hereinafter simply referred to as the first valve) is disposed, and a bypass-connected route (hereinafter referred to as the bypass route) is provided to the main route,
A normally closed second switching valve (hereinafter referred to simply as the second valve) is disposed between the bypass path and the main path so that the path is normally closed, and the circuit is opened when it is necessary to lower the brake fluid pressure. This bypass path includes a reservoir mechanism that receives the pressure of the incoming brake fluid and stores it while decreasing the fluid pressure by increasing the chamber volume, and a pump mechanism that pumps the fluid stored in this reservoir mechanism to the main path. The opening/closing operation of the first valve (normally open type) and the second valve (normally open type) is performed by an electronic control circuit that detects wheel lock during vehicle braking. It was designed to allow

By the way, in such a device, at the stage when the first valve is closed (that is, after the start of anti-lock control),
When the driver releases the brakes, if the first valve is held closed by the hydraulic pressure on the mask cylinder side, the hydraulic pressure inside the brake system will not release and the vehicle will not be able to run. There is a reason.

The present invention has been made to solve these difficulties, and its gist consists of a main path for transmitting brake fluid pressure connected between the mask cylinder and the brake device, and a main path for transmitting brake fluid pressure connected between the mask cylinder and the brake device. a normally open first valve that is interposed in the main path and closes the main path by electromagnetic operation; a bypass path that is connected to the main path by bypass between the first valve and the brake device; and one of the bypass paths. a second valve provided at the connection part of the bypass passage to open the opening with the main passage by electromagnetic operation; a pump mechanism provided at the other connection part of the bypass passage for pumping up liquid to the main passage side; In the wheel lock prevention device, the first reservoir mechanism of the main path is
Particularly, this invention relates to a wheel lock prevention device characterized in that a second pinox path is provided that bypasses the valve and only allows hydraulic pressure to return to the mask cylinder side.
This is effective when the first valve has a valve structure in which the valve body on the brake device side is seated on the valve seat on the mask cylinder side. Note that the second bypass path can be configured by providing a one-way valve such as a relief valve or a one-way seal such as a piston cup in the middle.

Embodiments of the present invention will be described below based on the principle configuration diagram shown in the drawings.

In the figure, 1 is a brake pedal, 2 is a mask cylinder that generates hydraulic pressure according to the pedal force, 3 is a hydraulic pressure transmission pipe that connects the mask cylinder 2 to the input port 4 of the valve device, and 6 is the output port of the valve device. 5 to brake device 7
These hydraulic pressure transmission pipes 3 and 6, including a flow path 8 that connects the input and output ports 4 and 5, form the main path. In the following explanation, these will be referred to as main paths 3 and 6.
It shall be shown as ゜8.

Reference numeral 9 denotes a normally open first valve interposed in the main path 8, a valve seat 10, and a valve body 11a1 formed in a part of the movable iron core 11.
It is composed of a hold spring 12 and a solenoid 13, and is normally provided so that the spring force of the hold spring 12 keeps the multi-flow path 8 in a normally open communication state, and when the solenoid 13 is energized, it changes to a closed state. Note that the timing of excitation of the solenoid 13 will be described later.

Reference numeral 14 denotes a pinous passage connected to the main passage 8 in the valve device, and a normally closed second valve 15 and a pump mechanism 21 for pumping up pressure liquid are connected as connection parts. has been done. Here, in the second valve 15, the valve body 18a is seated against the open valve seat 16 on the side of the main path 8 by the spring force of the hold spring 19, and the movable iron core 18 integrated with the valve body 18a acts as a solenoid. The valve body 18m is configured to be separated from the valve seat 16 when electromagnetically attracted by 2G excitation.

The pump mechanism 21 also includes, for example, a pair of tick valves 22.2.
3. It is composed of a reciprocating plunger 24, and an eccentric cam 25 that is assembled to a motor shaft or the like and rotates to cause the plunger 24 to reciprocate.

In addition, 26 is a reservoir mechanism interposed in the middle of the bypass path 14, and the reservoir piston 28 which is slidably fitted to the cylinder 27 is normally biased to a rest position by the spring force of the reservoir spring 29, and the pino'? When pressurized liquid flows into the gas path 14, the reservoir piston 28 moves against the spring force of the reservoir spring 29, thereby lowering the pressure value of the pressurized liquid.

The /rV feature of this example is a second bypass path in which a relief valve 31 is interposed between the input port 4 and the output port 5 of the main path to allow hydraulic pressure to flow back in the direction of the input port 4. The reason lies in the fact that there is a maximum of 30.

Next, the operation of the apparatus having the above configuration will be explained.

As is clear from the above, the brake fluid chamber generated in the mask cylinder during normal vehicle braking is
It is transmitted to the brake device via the input port 4 → the normally open first valve 9 → the output port 5, and generates the required braking force. At this time, the second valve 15 is normally closed. Also, the relief valve 30 does not function particularly well in this case.

By the way, in order to ensure such a normal operating state, it goes without saying that it is necessary to ensure that the first valve 9 is always kept open and the second valve 15 is always kept closed. The example of the present invention has the following advantages.

That is, for example, maintaining the second valve 15 normally closed is essentially provided by the spring thrust of the hold spring 19. On the other hand, it is the electromagnetic force applied by the solenoid 20 against the spring thrust that opens the second valve 15 when the brake fluid pressure needs to drop.

Therefore, if this electromagnetic force can be set small, the power consumption can be reduced, so it is desirable to set the thrust force of the hold spring 19 to be as small as possible.

However, as mentioned above, the second valve 15icl is a normally closed valve that partitions the main path 8 and the bypass path 14, and in order to maintain the normally closed state of the second valve 15icl, the valve may be closed depending on an external force other than the electromagnetic force. The holding spring 19 must be set so that it cannot open, and the hydraulic action from the main channel 8 is of particular concern here. The spring force must be set to a value that does not cause the valve body 18a to separate from the valve seat even when the hydraulic pressure is at its maximum value.

In this case, since the hydraulic pressure value is determined by the brake fluid pressure, it is desirable to minimize the area of action on the valve body 18a, and in this example, for this reason. In addition, a configuration is adopted in which the valve body 18a accommodated on the pias path 14 side is seated on a valve seat having a small diameter opening communicating with the main path 8 side, thereby reducing the set spring force of the hold spring 19. This makes it possible to reduce the required electromagnetic force.

Regarding the first valve 9, a movable iron core 1 having a valve body 11a is
1, since the hydraulic pressure in the axial direction acts in a balanced manner, the electromagnetic force of the solenoid 13 is small and insufficient.

Note that the first valve 9 is kept open when the flow direction of the hydraulic pressure is the valve body 1.
Since it acts in the direction of separating 1a from the valve seat 10, it can be reliably achieved by a light-loaded hold spring 1a.

During wheel lock prevention control, if this stage is divided into two stages: closing of the first valve 9 and opening of the second valve 15, first, the closing of the first valve 9 is performed by excitation of the solenoid 13; Since communication between input port 4 and output port 5 is cut off by
Regardless of whether the brake pedal 1 is pressed on the road, the brake fluid pressure in the pull/key device 7 will no longer rise. This operation can be electromagnetically performed extremely quickly as the valve body 11& is brought into contact with and seated on the valve seat 10 by the excitation of the solenoid 13.

It is necessary to set the excitation force of the solenoid 13 to be sufficiently large in order to maintain the first valve closed even when the hydraulic pressure on the brake device side decreases, which will be described later.

Next, when the solenoid 2o is energized, the movable iron core 18 moves to the left side of the figure against the hold spring 19.
The second valve 15 is opened.

Therefore, the brake pressure fluid flows into the reservoir mechanism, and the reservoir stone 28 begins to move against the spring thrust of the reservoir spring 29, causing a sudden drop in brake fluid pressure.

When the brake fluid pressure rises again during wheel lock prevention control, when the wheel lock is released due to a drop in brake fluid pressure, solenoid 2
The excitation of the valve o is stopped, and the second valve 15 returns to the normally closed state.

Therefore, the fluid stored in the reservoir mechanism is gradually pumped up to the main path 8 (brake device side) by the pump groove 21, and the brake fluid pressure rises again. When this recovers sufficiently, the first valve 9 is opened and the main path 8 is pumped up. to restore communication to normal,
The operation of the wheel lock prevention control ends.

Of course, if the wheels lock again during this process, the above operation will be repeated.

In the above control cycle, if the driver stops pressing the brake pedal 1 midway through the control cycle, a signal is generated to operate the first valve and the second valve for anti-lock control, for example. In the circuit where the brake pedal 1
When the road is released, the first valve 9 is activated.
The first valve may be returned to its initial state by the spring force of the hold spring 12 by canceling the operation and stopping the excitation of the snawachin renoids, but in the configuration of this embodiment, the first valve is If the hydraulic pressure is high to a certain extent, the first valve 9 may not be able to return to its initial position due to the liquid drop on the mask cylinder side. That is, the movable iron core 11 including the valve body 11a is suppressed by the hydraulic pressure on the brake device side and is pressed against the valve seat 1o of the valve body 11a.

However, in this example, in such a case, the relief valve 3
1 functions, the hydraulic pressure on the brake device side can be released to the mask cylinder side regardless of whether the first valve 9 is opened or closed.

Note that the first valve 9 in the wheel lock prevention device configured as above. To explain the operation control of the second valve 15, as already mentioned, the operation of the first valve 9 occurs in the initial stage when the wheel speed decreases beyond the appropriate level during vehicle braking. Therefore, for example, when the detected wheel speed signal vw shows a certain set deceleration gradient VT, or even higher deceleration, The first valve 9 is operated electromagnetically.

On the other hand, the operation of the second valve 15 is preferably performed when stopping the increase in brake fluid pressure by the operation of the first valve 9 described above is insufficient. Set a pseudo speed ■T2, which is a signal where ΔV=V, and whose rate of descent is regulated below a certain value,
vT2 and vw are compared, and when T2>vw, the second valve 15 is operated electromagnetically.

In this way, the brake fluid pressure can be maintained and further lowered selectively depending on the degree of decrease in the wheel speed VW, and desirable wheel brake force control can be achieved. Further, in this example, the operation of the first valve 9 and the second valve 15 can be stopped on the condition that vTl>vw for the former, and for the latter on the condition that ■7 has recovered to a certain value from the low peak. .

Note that the circuit structure for controlling the operation of the first valve and the second valve as described above can be formed by known electrical technology, and the operation control of the device of the present invention is limited to the above. It's not the purpose.

As described above, the wheel lock prevention device υ according to the present invention can obtain the above-mentioned various excellent effects with a relatively simple structure, and its usefulness is great. .

[Brief explanation of the drawing]

The drawing shows the basic principle of the wheel lock prevention device according to the present invention. 1 Brake pedal 2: Mask cylinder 3.6: Hydraulic pressure transmission pipe (main path) 4: Input port 5: Output port door: Brake device 8: Flow path (main path) 9: First valve
10: Valve seat work 1: Movable iron core 12: Hold spring 11a: Valve body 13: Solenoid 14: Bypass path 15: Chain 2 valve 16: Valve seat 18: Movable iron core 18a: Valve body
19: Hold spring 20: Solenoid 21: Pump mechanism 22.23: Check valve
24: Zoranger 25: Eccentric cam 26: Reservoir mechanism 27: Cylinder 28: Reservoir piston 29
:Reservoir spring 30:Second bypass path 31
: Relief valve

Claims (1)

[Claims] a main path for transmitting brake fluid pressure connected between the mask cylinder and the brake device; a normally open first valve that is interposed in this main path and closes the main path by electromagnetic operation;
A pinos path connected by bypass to the main path between the valve and the brake device, and a second valve provided at one connection part of the bypass path to open an opening with the υ main path by electromagnetic actuation. , a wheel lock prevention device including a pump mechanism provided at the other connecting portion of the pie-yas path and pumping liquid to the main path side, and a reservoir mechanism in the bypass path, the first valve of the main path being A wheel lock prevention device characterized in that a second bypass path is provided that bypasses the flow of fluid pressure and only allows hydraulic pressure to flow back to the mask cylinder side.